LastLogin.find_by_sql "DELETE FROM last_logins WHERE date < (SELECT date FROM last_logins ORDER BY
date DESC OFFSET 4 LIMIT 1)"
\d last_logins
Table "public.last_logins"
Column | Type | Modifiers
---------+-----------------------------+----------------------------------------------------------
user_id | integer |
date | timestamp without time zone | default now()
id | integer | not null default nextval('last_logins_id_seq'::regclass)
Indexes:
"last_logins_pkey" PRIMARY KEY, btree (id)